The present invention relates to an ultrasonic probe in which piezoelectric elements are arrayed in a two dimensional form, and in particular to an ultrasonic probe in which lead wires are led out with a high degree of accuracy, and to a manufacturing method therefor.
Ultrasonic probes are widely used, for example, as the ultrasonic transmitting and receiving section in medical diagnostic equipment. As such equipment, there are those which have piezoelectric elements arrayed in a two-dimensional form and which scan electronically in a two-dimensional direction for high resolution.
FIG. 6 is a perspective view for explaining a conventional ultrasonic probe.
This ultrasonic probe comprises a plurality of piezoelectric elements 1a, 1b and 1c arrayed on the upper surface of a fixing base 2 in a two-dimensional direction (lengthwise direction (X) and widthwise direction (Y)). Each of the piezoelectric elements 1a, 1b and 1c has driving electrodes 3a and 3b on both of their principal surfaces (upper surface and lower surface). The fixing base 2 normally comprises a damper material such as rubber that has a vibration damping function for inhibiting vibration, to prevent reflection of ultrasonic waves. Generally, the damper material is called a backing material. Moreover, a lead wire 4 is connected to the driving electrode 3b provided on the lower surface of the piezoelectric element 1, and passes through the fixing base 2 and is led out to the back side thereof. Here, the lead wire 4 is exposed on the back side of the fixing base 2, and is connected to a power supply cable by a connector (not shown).
In order to manufacture such a conventional ultrasonic probe, first of all, for example as shown in FIG. 7, a plurality of comb shaped integrated lead wires 4A in which the lead wires 4 are formed from a thin plate and are connected by a connection portion 5, are arrayed in parallel, inside a mold box (not shown). Then, a damper material of synthetic resin that constitutes the fixing base 2, is poured into the mold box, and allowed to harden to integrate the integrated lead wires 4A. Next, both principal surfaces (upper surface and lower surface) of the damper material are ground to expose the connection portion 5 and a rear end portion of the integrated lead wire 4A [Refer to Japanese Unexamined Patent Publication(TOKKYO KOKAI)No. Hei 10-282074 (Japanese Patent No. 3507655)].
Finally, a piezoelectric plate 6 is fixed to the one principal surface of the fixing base 2 which had the connection portion 5 exposed, and the areas between the respective lead wires 4 and between the integrated lead wires 4A are cut away to divide up the fixing base 2 into individual piezoelectric elements 1a, 1b and 1c (see FIG. 6). As a result, the electrically connected lead wires 4 are led out from the lower surface of the individual piezoelectric elements 1.
However, in the conventional ultrasonic probe of the above construction, since a damper material is used as the fixing base 2, then for example when connecting the lead wires 4 exposed on the underside, to the connector (not shown) using solder, the connection operation becomes difficult due to a lack of heat resistance. Moreover, accurately aligning the comb shaped integrated lead wire 4A inside the mold box is difficult. Therefore, there is a problem in that array accuracy of the lead wires 4 is reduced, and so forth.
An object of the present invention is to provide an ultrasonic probe in which the array accuracy of the lead wires, and the heat resistance when connecting to a connector are enhanced, and a manufacturing method therefor.